Dark Tides (The Fairmile #2)
Philippa Gregory

The second visitor is a beautiful widow from Venice in deepest mourning. She claims Alinor as her mother-in-law and tells her of the death of Rob—Alinor’s son—drowned in the dark tides of the Venice lagoon.
Meanwhile, Alinor’s brother Ned, in faraway New England, is making a life for himself between in the narrowing space between the jarring worlds of the English newcomers and the American Indians as they move towards inevitable war. Alinor writes to him that she knows—without doubt—that her son is alive and the widow is an imposter. But how can she prove it?
Set in the poverty and glamour of Restoration London, in the golden streets of Venice, and on the tensely contested frontier of early America, this is a novel of greed and desire: for love, for wealth, for a child, and for home.